A biogas cleaning method for purifying a biogas waste stream to form a combustible clean biofuel uses a biogas cleaning system that includes a gas control system, a deoxidizer catalyst bed, a hydrosulfurization catalyst bed, a hydrogen sulfide adsorption bed and a thermal sensor controller. The biogas cleaning method includes using a biogas source to introduce a biogas waste stream into the biogas cleaning system, blending hydrogen with the biogas waste stream, combusting the blended hydrogen and biogas stream to remove oxygen, hydrogenating the heated biogas waste stream to convert sulfur species to hydrogen sulfide and adsorbing the hydrogen sulfide from the biogas stream. In some embodiments, a biogas cleaning system also includes a sulfur polisher adsorption bed, a chlorine removal adsorption bed, a siloxane removal adsorption bed, a heat exchanger loop and a biogas precooler. Some embodiments of a biogas cleaning method can also include precooling the biogas waste stream, adsorbing siloxanes from the biogas waste stream and adsorbing hydrogen chloride from the biogas stream.

A method, scrubbing solution and apparatus for removing a H.sub.2S scavenger, for example dithiazine, from a gas stream uses an acidic solution to convert the H.sub.2S scavenger to a salt. The acidic solution may be a phosphoric acid solution.

The invention relates to a method for preparing a solid comprising a step of mixing a set of compounds comprising at least two Cu.sub.2(OH).sub.2CO.sub.3 powders of different particle sizes and at least one binder and the use of the solid prepared by means of this method.

A filtering device is provided for filtering pollutants from a gas stream. The device includes a cartridge comprising an inner perforated passage, an outer perforated jacket, one or more non-perforated ends and a sorbent bed contained between the inner passage and the outer jacket; and a outer shell containing the cartridge and having a first port in fluid communication with the inner perforated passage and a second port in fluid communication with the outer perforated jacket. A flowpath of the gas stream into any one of the first port or the second port, through the sorbent bed and out of the other of the first port or the second port is a bidirectional flowpath. A method is further provided for filtering pollutants from a gas stream. The method includes the steps of allowing the gas stream to flow into a filtering device in a first direction, the device comprising a cartridge having a sorbent bed contained therein; directing the gas stream to bend in a second direction differing from the first direction as it enters the sorbent bed; and allowing the gas stream to pass through the sorbent bed and to exit the device.

Various embodiments disclosed relate to extraction of target materials using a CZTS sorbent. A method of extracting a target material from a medium includes contacting a copper zinc tin sulfur (CZTS) sorbent with the target material in the medium including the target material to form a used CZTS sorbent that includes the target material. The method also includes separating the used CZTS sorbent from the medium.

Sorbent compositions containing calcium and iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.

A scrubber for cleaning a gas comprises a casing extending along a longitudinal central axis and enclosing a scrubbing chamber. The casing has a gas inlet and a gas outlet. The casing is configured to permit flow of the gas through the scrubbing chamber in a flow direction from the gas inlet to the gas outlet. A deflector device in the scrubbing chamber between the gas inlet and outlet forms a gas passage between the deflector device and the casing. The deflector device comprises an upstream surface facing the gas inlet. A spraying nozzle is configured to spray a scrubbing liquid into the scrubbing chamber and the gas flow. A separation device comprises a shield element and is arranged between the upstream surface of the deflector device and the gas inlet. The shield element shields the upstream surface from the gas flow and is perforated by a plurality of holes.

A scrubber for cleaning of a gas comprises a casing, enclosing a scrubbing chamber. The casing comprises a gas inlet into and a gas outlet out from the scrubbing chamber. The casing permits the gas to flow through the scrubbing chamber from the gas inlet to the gas outlet. A deflector device is provided in the scrubbing chamber between the gas inlet and the gas outlet and forms a passage between the deflector device and the casing. The deflector device comprises a downstream surface facing the gas outlet and having an outer edge. A spraying nozzle is configured to spray a scrubbing liquid into the scrubbing chamber and the gas flow. A channel member extends from the deflector device. The channel member leads scrubbing liquid collected by the deflector device from the deflector device.

Methods and systems to decarbonize natural gas using sulfur to produce hydrogen and polymers are provided. Sulfur can be introduced in elemental form or as hydrogen sulfide, as may be desired. Decarbonization of natural gas involves introducing natural gas and H.sub.2S to a first reactor to produce first reactor products including CS.sub.2 and H.sub.2. The CS.sub.2 can subsequently be polymerized and the H.sub.2 recovered in a purified form with little or no carbon emissions.

A scrubber for cleaning of a gas comprises a casing enclosing a scrubbing chamber. The casing comprises a gas inlet into and a gas outlet out from the scrubbing chamber. A gas flow of the gas flows through the scrubbing chamber in a flow direction from the gas inlet to the gas outlet. A deflector device is provided in the scrubbing chamber between the gas inlet and the gas outlet and forms a passage between the deflector device and the casing. A spraying nozzle is arranged between the gas outlet and the deflector device for spraying a scrubbing liquid into the scrubbing chamber and the gas flow. An inner shield extends between the casing and the deflector device, surrounds the deflector device at least partly, and forms a gap with the casing. Scrubbing liquid may flow through the gap.